Obsessive
by Coyoyotie
Summary: In which Regulus just wants to buy his mother's Yule gift. Sensitive topic challenge; OCD, one-shot.


Harry Potter does not belong to me, nor does poor Regulus who is the unfortunate object of my tampering.  
Warnings are Obsessive-Compulsive Disorder with negative thinking involving death.

Topic: OCD  
Prompts: yellow, smashed window, fingerprint

* * *

**Diagon Alley was a hard** place for Regulus Black to be. Unlike the constantly changing and moving market stalls, the shops at least stayed in the same place every time he visited. The people were horrid too, in their colourful robes and, even worse, Muggle clothes. There were always owls swooping back and forth unpredictably, heading toward and away from the owl office, and sometimes the children would get their toys out of the bags and wave them around as they walked.

After all, with the huge range of ever-changing colours and patterns, there was always going to be some yellow and green – the bright, lime shade – that could be beside each other. The yellow alone was bad enough, untouchable at best, but with the two tones mixing...

Unfortunately, he didn't have a choice but to go; he needed to call by Gringotts bank to withdraw a handful of Galleons and then collect his mother's Yule present. It was a rare book on poisonous magical flowers that he knew she'd been wanting – Kreacher had found it in an old bookstore down Knockturn and had it reserved for the wizard.

The Slytherin shuddered as he passed a stand advertising poor quality potions, though he was avoiding the sunshine-coloured sign rather than the bad merchandise. Merlin, people were so ignorant.

With his eyes facing forwards and slightly up, Regulus walked determinedly down the street. He couldn't allow himself to see the cobblestone road he walked upon; it was made of stones too small to walk comfortably between the cracks, and it would take a good two hours to walk the length of the alley. Not to mention how absurd he would look, tip-toeing down the street and leaping from stone to stone, arms flailing to avoid unbalancing for fear of landing wrong.

If he touched the cracks between the rocks, his mother might get ill.

Yellow will bring disease. Yellow and green together invite a funeral.

He remembered once, when he was just twelve and was crossing a Muggle area between where the Knight Bus dropped him and the back entrance to Diagon, he'd passed a stone yellow dog with a slit in its head and a sign around its neck, advertising a charity. At first, Regulus had cowered away and hurried his step, but then he remembered what his aunt had been saying that morning about how his brother was a disgrace to the family name, and how he should be 'gotten rid of' properly to make dear Regulus the family heir.

Face screwed up in fear, a single pinky reached out and barely brushed the dog's ear. One eye opened very slightly, as if expecting there to be yellow sinking into his fingerprint, and then his mouth dropped in horror. There was a fluorescent green harness on the dog's back.

Merlin, what had he done? Sirius was going to get dragon pox, and it would infect the whole family and it would be his fault, and they would all die and he'd have to attend the funerals which would make more people die, and he'd be alone and it was all because of _him!_

Quickly, the young boy began tapping his hands together in certain formations, and then his feet were carefully placed as he span away, dancing down the street and touching certain loose pebbles and double-tapping certain bricks in the wall, all in an effort to negate his foolish touch of the green and yellow, to prevent the death of all his loved ones.

Back in the present, Regulus shuddered again. _Life,_ he thought, because he'd just thought the word 'death' which could also cause someone to die, and he needed to prevent it. _Pathetic,_ he then continued, but he knew he'd rather be a bit odd than risk the chance of anything bad happening.

A sigh of relief left him as he flew over the steps at Gringotts' entrance. The whole hall was floored in marble, smooth and without lines. The goblins, ever so strict and stern, would never have a pile of paperwork out of place. Everything was done in rituals, timed automatically and just so absolutely _perfect_.

In the privacy of his vault, Regulus carefully took a gold Galleon from each of the stacks, keeping them all identical in height. He had to force his bag to close, but it was worth it. With one last poke to a pile of Knuts that had begun to lean slightly to the left, the wizard returned to the cart which would move much too quickly for him to notice any bad objects (though he didn't know if that was a good or bad thing).

Less than a metre from the door now stood a stall selling candies of all different kinds, handmade rather than professionally done Honeydukes products, which had obviously been moved during his money collecting. In front of it, with three toffee apples sticking out from between the fingers of each hand, twirled a reasonably large lady dressed in disgusting Muggle garb as she called out tempting prices to the children and parents passing by.

He had barely glanced at her, but it was as if his brain was created already wired to detect danger – his legs had automatically frozen at the sight, even as his eyes roamed toward the safe sky. Looking back at what he'd subconsciously noticed, he counted the clear thirteen – _fire!_ – horizontal stripes of colour that ran across her skirt.

After standing at the same spot for about thirty seconds, shifting and rummaging as if he was putting his money pouch away and adjusting his robe for the longest acceptable time without looking awkward, Regulus sidestepped and slid down the right side of the steps. He hugged the wall and passed the guard goblin as close as his self preservation allowed him to before darting into the side alley.

The alley was long and cold, leading round to the far end of Knockturn in a loop past the back sides of Diagon's shops. There were doors sporadically along the left wall, each leading to the private sections of the shop buildings – some were first floor flats, others offices and storage.

With thirteen already at the front of his mind, it was no surprise when his body was quivering as he came to the thirteenth door. It was blue, which was fine, but it was only a few feet beyond it that the alley sloped downwards to a set of stairs.

_Merlin, why is there exactly thirteen? Any number, anything else..._ Because he knew the number one-three was linked to fire, and fire _kills_, and – and there were _thirteen doors!_

When Regulus had come down this alley a few years prior, he was being dragged by his big brother who had been charged to take care of him. It was a rare moment when Sirius stopped talking, especially when he was excited about meeting up with his Gryffindor friends, so the twitchy child was barely able to focus on keeping up with his rambunctious sibling, let alone counting doorways. And the time after that he was being led by his mother, and he daren't show anything less than perfection and poise in front of her and her high standards.

With no way around it, trapped between the thirteenth door and the thirteen striped lady, Regulus resorted to rituals as he jolted past. One hand came up to tap, tap-tap, tap on his ribs whilst the other circled whichever bricks his mind deemed necessary, fingers trailing over each patch of dark moss but steering clear of any ivy vines.

Exhaling with chagrined pride at having gotten past the obstacle, he made his way quickly down the narrow stairway, ready to slip into the bookstore, swiftly exchange eight Galleons for the book, escape the shop wards, and Apparate home. Except, the last step... was the thirteenth.

Already, barely milliseconds after recognising it as the third set of the ghastly number, anxiety and thoughts and images began pouring into his mind. There was fire, first and foremost, covering everything in sight – and he knew it was spilling into places he couldn't see. There were ferocious flames roaring out of the open door, spreading easily without anything holding it back, and the glass couldn't stand the heat, wards or no, and the broken windows were orange and _yellow_ with the fire!

His beloved mother and father, sometimes-hated brother, kind uncle and maybe even his beautiful cousins were all inside the burning building, which was choked with billowing black smoke and beginning to collapse in on itself. Fiendfyre, it had to be – nothing could control the spitting inferno! If he couldn't avoid a _freaking number_, how the hell could he keep his family alive?

No, he couldn't do this. He had no distractions, no one to act for, no ritual good enough for three sets of thirteen. Regulus was trembling with fear and repulsion, unable to move without disturbing the perfect count of twelve steps that he'd taken – one more and it'd be thirteen again – Fire! _Fire!_

Regulus twisted himself, spinning into nothingness as he Apparated to the safety of his perfectly designed room.

Merlin be damned, Kreacher could get the bloody book instead.


End file.
